it has a proof look to it....someone must have cracked it out of a set
although a clean coin and in nice condition I feel you might invest in certification for higher value coins, common date mint state coins such as this are valued modestly under a hundred dollars and it would be cost prohibitive to spend on slabbing this one
put it in a 2x2 and enjoy it in your collection
great find out in the wild
stunning!! sold a '57-P in that condition on Ebay for abooot $26 a few years ago. older full steps with full luster are worth at least a few rolls of nickels